Image forming system, image forming apparatus, terminal device, gradation characteristic measuring method, computer readable medium storing program and gradation characteristic measurement sheet

ABSTRACT

A terminal device includes: a colorimetry unit that performs colorimetry on color values of respective measurement regions on a gradation characteristic measurement sheet where the plural measurement regions are formed in different densities; and a determination unit that determines identification information to identify the gradation characteristic measurement sheet based on a result of colorimetry of identification information measurement regions arranged to identify the gradation characteristic measurement sheet in a result of colorimetry by the colorimetry unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2008-236172 filed Sep. 16, 2008.

BACKGROUND Technical Field

The present invention relates to an image forming system, an imageforming apparatus, a terminal device, a gradation characteristicmeasuring method, a computer readable medium storing a program and agradation characteristic measurement sheet.

SUMMARY

According to an aspect of the invention, there is provided a terminaldevice including: a colorimetry unit that performs colorimetry on colorvalues of respective measurement regions on a gradation characteristicmeasurement sheet where the plural measurement regions are formed indifferent densities; and a determination unit that determinesidentification information to identify the gradation characteristicmeasurement sheet based on the result of colorimetry of identificationinformation measurement regions arranged to identify the gradationcharacteristic measurement sheet in a result of colorimetry by thecolorimetry unit.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 illustrates a system configuration of an image forming systemaccording to an exemplary embodiment of the present invention;

FIG. 2 is a block diagram showing a hardware configuration of an imageforming apparatus 10 in the exemplary embodiment of the presentinvention;

FIG. 3 is a block diagram showing a functional configuration of theimage forming apparatus 10 in the exemplary embodiment of the presentinvention;

FIG. 4 is a block diagram showing a hardware configuration of a terminaldevice 20 in the exemplary embodiment of the present invention;

FIG. 5 is a block diagram showing a functional configuration of theterminal device 20 in the exemplary embodiment of the present invention;

FIG. 6 is a flowchart showing processing upon output of a color chart bythe image forming apparatus 10;

FIG. 7 is a flowchart showing processing upon colorimetry on respectivepatches in the color chart 90 outputted by the image forming apparatus10, in the terminal device 20;

FIG. 8 is a flowchart showing processing upon generation of calibrationdata in the image forming apparatus 10 which has received a colorimetricdata file from the terminal device 20;

FIG. 9 shows an example of the color chart 90 used in the image formingsystem according to the exemplary embodiment of the present invention;

FIG. 10 is an explanatory view showing contents of identificationinformation indicated with respective patches of an identificationinformation patch 82 in the color chart shown in FIG. 9;

FIG. 11 shows an example of relation between the array of theidentification information patch 82 and corresponding identificationinformation;

FIG. 12 shows an example a color chart having two types of black andwhite patches in place of the color patch as the identificationinformation patch;

FIG. 13 is an explanatory view showing the structure of anidentification information patch 83 in the color chart 91 shown in FIG.12; and

FIG. 14 is an explanatory view showing subject tray information in theidentification information patch 83.

DETAILED DESCRIPTION

Next, an exemplary embodiment of the present invention will be describedin detail based on the drawings.

FIG. 1 illustrates a system configuration of an image forming systemaccording to the exemplary embodiment of the present invention.

As shown in FIG. 1, the image forming system according to the exemplaryembodiment of the present invention has an image forming apparatus 10and a terminal device 20 interconnected via a network 30. Note that itmay be arranged such that the terminal device 20 and the image formingapparatus 10 are not directly connected and a controller (print controldevice) is provided therebetween. In the present exemplary embodiment,however, the function of the controller is included in the image formingapparatus 10.

The terminal device 20 generates print data and transmits the generatedprint data via the network 30 to image forming apparatus 10. The imageforming apparatus 10 receives the print data transmitted from theterminal device 20, and outputs an image corresponding to the print dataon a print sheet. Note that the image forming apparatus 10 may be aso-called multifunction device having plural functions of a printfunction, a scan function, a duplication (copying) function, a facsimilefunction and the like.

When gradation correction (calibration) is performed, the image formingapparatus 10 print-outputs a color chart (gradation characteristicmeasurement sheet) 90 in which plural patches (measurement regions) indifferent densities are provided for gradation characteristicmeasurement.

The terminal device 20, connected to a chromatometer 21, performscolorimetry on color values of the respective patches in the color chart90 printed by the image forming apparatus 10. The colorimetric dataobtained by the terminal device 20 is transferred via the network 30 tothe image forming apparatus 10, and calibration data for gradationcorrection is generated.

Next, FIG. 2 shows a hardware configuration of the image formingapparatus 10 in the image forming system in the present exemplaryembodiment.

As shown in FIG. 2, the image forming apparatus 10 has a CPU 11, amemory 12, a storage device 13 such as a hard disk drive (HDD), acommunication interface (IF) 14 for data transmission/reception betweenthe image forming apparatus 10 and an external device or the like viathe network 30, a user interface (UI) device 15 including a touch panelor a liquid crystal display and a keyboard, and a print engine 16. Theseconstituent elements are interconnected via a control bus 17.

The CPU 11 performs predetermined processing based on a control programstored in the memory 12 or the storage device 13 to control theoperation of the image forming apparatus 10.

Note that in the present exemplary embodiment, the CPU 11 reads thecontrol program stored in the memory 12 or the storage device 13 andexecutes the program. However, it may be arranged such that the programis stored on a storage medium such as a CD-ROM and provided to the CPU11.

FIG. 3 is a block diagram showing a functional configuration of theimage forming apparatus 10 realized by execution of the above-describedcontrol program.

As shown in FIG. 3, the image forming apparatus 10 in the presentexemplary embodiment has a gradation characteristic measurement patchdata storage part 31, a correspondence table storage part 32, a colorchart image combining part 33, an identification information patch datageneration part 34, an image output part 35, a colorimetric datareception part 36, a calibration data generation part 37, a calibrationdata storage part 38, and a gradation correction processing part 39.

The gradation characteristic measurement patch data storage part 31holds gradation characteristic measurement patch data for printingplural gradation characteristic measurement patches for gradationcharacteristics measurement.

The correspondence table storage part 32 holds information indicatingcorrespondence between the array of identification information patchesand identification information represented with the array.

The identification information patch data generation part 34 generatesidentification information patch data, in which patches are arrayed in aparticular order, by referring to a correspondence table stored in thecorrespondence table storage part 32, based on identificationinformation to identify a color chart for gradation characteristicmeasurement.

Note that as such identification information, at least one ofinformation to specify an image forming apparatus which has outputtedthe color chart, destination information, type information of gradationcharacteristic measurement patch for gradation characteristicmeasurement, time information of time at which the color chart has beenoutputted, information to specify a subject tray or subject print sheetto which gradation correction is to be applied, or a combination ofthese information pieces can be given.

The color chart image combining part 33 combines identificationinformation patch data generated by the identification information patchdata generation part 34 with gradation characteristic measurement patchdata for gradation characteristic measurement.

The image output part 35 outputs the color chart 90 for gradationcharacteristic measurement based on the image data combined by the colorchart image combining part 33.

The colorimetric data reception part 36 receives colorimetric data asthe result of colorimetry of respective patches in the color chart 90from the terminal device 20.

The calibration data generation part 37 generates calibration data forcalibration (gradation correction) processing based on the colorimetricdata of the gradation characteristic measurement patches received by thecolorimetric data reception part 36.

The calibration data storage part 38 holds the calibration datagenerated by the calibration data generation part 37. Note that thecalibration data storage part 38 refers to identification informationincluded in the colorimetric data, and holds the calibration data,together with information on a subject tray, subject print sheet or thelike to which calibration is to be applied.

The gradation correction processing part 39 performs calibration(gradation correction) processing on print data to be outputted to theimage output part 35 based on the calibration data generated by thecalibration data generation part 37.

Next, FIG. 4 shows a hardware configuration of the terminal device 20 inthe image forming system according to the present exemplary embodiment.

As shown in FIG. 4, the terminal device 20 has a CPU 41, a memory 42, astorage device 43 such as a hard disk drive (HDD), a communicationinterface (IF) 44 for data transmission/reception between the terminaldevice 20 and an external device or the like via the network 30, and auser interface (UI) device 45 including a touch panel or a liquidcrystal display and a keyboard. The constituent elements areinterconnected via a control bus 46.

The CPU 41 performs predetermined processing based on a control programstored in the memory 42 or the storage device 43, to control theoperation of the terminal device 20.

Note that in the present exemplary embodiment, the CPU 41 reads thecontrol program stored in the memory 42 or the storage device 43 andexecutes the program. However, it may be arranged such that the programis stored on a storage medium such as a CD-ROM and provided to the CPU41.

FIG. 5 is a block diagram showing a functional configuration of theterminal device 20 realized by execution of the above-described controlprogram.

As shown in FIG. 5, the terminal device 20 in the present exemplaryembodiment has a colorimetry controller 51, an identificationinformation determination unit 52, a correspondence table storage part53, and a colorimetric data transmission unit 54.

The colorimetry controller 51 controls the chromatometer 21 connected toan external device, to perform colorimetry on the color values ofrespective patches formed in the color chart 90.

As in the case of the correspondence table storage part 32 shown in FIG.3, the correspondence table storage part 53 holds information indicatingcorrespondence between an array of identification information patchesand identification information represented with the array.

The identification information determination unit 52 refers to acorrespondence table stored in the correspondence table storage part 53,and determines identification information to identify the color chart 90(or attribute information indicating an attribute of the color chart90), based on colorimetric data of the identification informationpatches arrayed for identification of the color chart 90, in thecolorimetric data as the result of colorimetry by the chromatometer 21and the colorimetry controller 51.

The colorimetric data transmission unit 54 transmits the colorimetricdata as the result of colorimetry by the chromatometer 21 and thecolorimetry controller 51, with the identification informationdetermined by the identification information determination unit 52, tothe image forming apparatus 10.

Next, the operation of the image forming system according to the presentexemplary embodiment will be described in detail with reference to thedrawings.

First, processing upon output of the color chart by the image formingapparatus 10 will be described with reference to the flowchart of FIG.6.

When the image forming apparatus 10 receives an instruction to outputthe color chart for calibration from the terminal device 20 (step S101),the identification information patch data generation part 34 in theimage forming apparatus 10 generates identification information patchdata where patches are arrayed in correspondence with identificationinformation to be embedded in the color chart (step S102).

Then, the color chart image combining part 33 generates a color chartimage by combining the identification information patch data generatedby the identification information patch data generation part 34 withgradation characteristic measurement patch data stored in the gradationcharacteristic measurement patch data storage part 31 (step S103).

Then, based on the color chart image combined by the color chart imagecombining part 33, print processing is performed by the image outputpart 35, and the color chart 90 is outputted (step S104).

Next, processing upon colorimetry of the respective patches in the colorchart 90, outputted by the image forming apparatus 10, in the terminaldevice 20 will be described with reference to the flowchart of FIG. 7.

When colorimetry software is started in the terminal device 20 (stepS201), the colorimetry controller 51 controls the chromatometer 21 tostart colorimetry of the color chart (step S202).

Then, the colorimetry controller 51 sets the chromatometer 21 into aspot colorimetric mode to perform colorimetry of each patch, andperforms colorimetry on the identification information patches (stepS203). Then the identification information determination unit 52determines the identification information embedded in the array of theidentification information patches, based on the result of colorimetryof the identification information patch and the correspondence tablestored in the correspondence table storage part 53 (step S204).

Next, the colorimetry controller 51 sets the chromatometer 21 into astrip colorimetric mode to continuously perform colorimetry on one arrayof patches, and performs colorimetry on the gradation characteristicmeasurement patches (step S205).

Note that when the identification information determined at step S204includes gradation characteristic measurement patch information, theinformation is transmitted to the colorimetry controller 51, and thecolorimetry controller 51 performs colorimetry on the gradationcharacteristic measurement patches based on the gradation characteristicmeasurement patch information.

Then, when the colorimetry of all the patches formed in the color chart90 has been completed (step S206), a colorimetric data file includingthe determined identification information is generated (step S207), andthe colorimetric data file is transferred to the image forming apparatus10 by the colorimetric data transmission unit 54 (step S208).

When the identification information determined by the identificationinformation determination unit 52 includes destination information suchas ID information and a network address of a printer which has outputtedthe color chart 90, the image forming apparatus 10 transfers thecolorimetric data using the destination information.

Next, processing upon generation of calibration data in the imageforming apparatus 10 which has received the colorimetric data file fromthe terminal device 20 will be described with reference to the flowchartof FIG. 8.

When the colorimetric data file transferred by the terminal device 20 isreceived by the colorimetric data reception part 36 in the image formingapparatus 10 (step S301), the calibration data generation part 37compares the result of colorimetry of the respective patches included inthe colorimetric data with reference values, and generates calibrationdata for correction of a gradation characteristic of the image outputpart 35 (step S302) and stores the calibration data into the calibrationdata storage part 38 (step S303). The calibration data previously storedin the calibration data storage part 38 is updated with the currentlystored calibration data, and a shift of the gradation characteristic ofthe image output part 35 is corrected.

It may be arranged such that when ID information and network addressinformation of the image forming apparatus are embedded in theidentification information included in the colorimetric data from theterminal device 20, and they are different from the ID information andthe network address of an image forming apparatus to be subjected tocalibration, the calibration data generation part 37 issues a warning orinterrupts the processing.

Further, it may be arranged such that, upon output of a new color chart,when a color chart output number and output time information which areupdated upon each output are embedded as identification information inthe color chart, the calibration data generation part 37 checks thecolor chart output number and the output time information embedded inthe identification information included in the colorimetric data filetransferred from the terminal device 20. In this case, when the colorchart output number and the output time information do not correspondwith the color chart output number and the output time informationembedded in a immediately-previously outputted color chart, thecalibration data generation part 37 issues a waning or interrupts theprocessing.

Next, FIG. 9 shows an example of the color chart 90 used in the imageforming system according to the present exemplary embodiment. In thecolor chart 90 shown in FIG. 9, a gradation characteristic measurementpatch 81 and an identification information patch 82 are formed.

The gradation characteristic measurement patch 81 has plural patches inwhich YMCK densities are changed stepwisely. In the identificationinformation patch 82, patches in 100% YMCK densities are arrayed in aparticular order so as to represent identification information of thecolor chart 90.

More particularly, as shown in FIG. 10, the initial four patches (1A to1D) indicate YMCK reference colors, and the fifth patch (1E) indicatesthe end of the reference colors. Further, the sixth patch (1F) indicatesa patch type, and the seventh and eighth patches (1G and 1H) indicatesubject tray information. The ninth to twelfth patches (1I, 1J, 2A and2B) indicate an output printer specific ID (ID information of an imageforming apparatus), and the thirteenth patch (2C) indicates a check sum.

FIG. 11 shows an example of relation between the array of theidentification information patch 82 and indicated identificationinformation. The identification information determination unit 52 candetermine contents of various information included in the identificationinformation from the correspondence table as shown in FIG. 11 and thearray of the identification information patch 82. For example, as theseventh and eighth patches (1G and 1H) indicating subject trayinformation are respectively Y (yellow)=#0 and M (magenta)=#1 patches,it can be determined by referring to FIG. 11 that the subject trayinformation indicates #0#, i.e., a tray 2.

Further, FIG. 12 shows an example of a color chart 91 having two typesof black and white patches in place of the color patches as theidentification information patch. The color chart 91 shown in FIG. 12has the gradation characteristic measurement patch 81 and anidentification information patch 83. The identification informationpatch 83 shown in FIG. 12 is not a fixed patch in which the number ofpatches is fixed but is a variable patch in which the number of patchesvaries in accordance with embedded information.

As shown in FIG. 13, the identification information patch 83 has twoblack patches 71 and 72 and plural white patches divided with the twoblack patches 71 and 72. The number of first continuous white patchesindicates the subject tray information, and the number of secondcontinuous white patches indicates the output printer specific IDinformation. That is, the two black patches 71 and 72 indicate endpositions of the subject tray information and the output printerspecific ID information.

As shown in FIG. 14, the subject tray information indicates, with thenumber of continuous white patches before the occurrence of the blackpatch 71, the subject tray information to specify a tray to whichcalibration data is to be applied. That is, when the number ofcontinuous white patches is 1, the subject tray is a tray 1; when thenumber of continuous white patches is 2, 3, or 4, the subject tray isthe tray 2, a tray 3, or a tray 4.

[Modification]

In the above-described exemplary embodiment, colorimetry is performed onthe identification information patches 82 and 83 prior to the gradationcharacteristic measurement patch 81, however, the present invention isnot limited to this arrangement. For example, the present invention isapplicable to a case where colorimetry is performed on the gradationcharacteristic measurement patch 81 prior to the identificationinformation patches 82 and 83.

Further, in the example of the color chart 90 shown in FIG. 9, one ofthe YMCK patches indicates the information #0 to #3, however, acombination of two of the YMCK patches may indicate the information #0to #3. For example, when it is prescribed that Y and M=#0, M and C(cyan)=#1, C and K (black)=#2, and Y=#3, even though a print sheet has adeep color and one of two patches of the YMCK patches is notdiscriminable, correct information can be guessed as long as the otherone of the two patches is discriminable.

The foregoing description of the exemplary embodiment of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theexemplary embodiment was chosen and described in order to best explainthe principles of the invention and its practical applications, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

1. A terminal device comprising: a colorimetry unit that performscolorimetry on color values of respective measurement regions on agradation characteristic measurement sheet where the plurality ofmeasurement regions are formed in different densities; and adetermination unit that determines identification information toidentify the gradation characteristic measurement sheet based on aresult of colorimetry of identification information measurement regionsarranged to identify the gradation characteristic measurement sheet, ina result of colorimetry by the colorimetry unit.
 2. The terminal deviceaccording to claim 1, further comprising a storage unit that holdsinformation indicating correspondence between an array of theidentification information measurement regions and identificationinformation indicated with the array, wherein the determination unitdetermines the identification information by using the informationstored in the storage unit.
 3. The terminal device according to claim 1,wherein the identification information includes at least one ofinformation to specify an image forming apparatus which has outputtedthe gradation characteristic measurement sheet, destination information,type information of the gradation characteristic measurement regions forgradation characteristic measurement, time information of time at whichthe gradation characteristic measurement sheet has been outputted, andinformation to specify a subject tray or a subject sheet to whichgradation correction is to be applied.
 4. The terminal device accordingto claim 2, wherein the identification information includes at least oneof information to specify an image forming apparatus which has outputtedthe gradation characteristic measurement sheet, destination information,type information of the gradation characteristic measurement regions forgradation characteristic measurement, time information of time at whichthe gradation characteristic measurement sheet has been outputted, andinformation to specify a subject tray or a subject sheet to whichgradation correction is to be applied.
 5. An image forming apparatuscomprising: a generation unit that generates identification informationmeasurement region data in which measurement regions are arrayed basedon identification information to identify a gradation characteristicmeasurement sheet for gradation characteristic measurement; a combiningunit that combines the identification information measurement regiondata generated by the generation unit with gradation characteristicmeasurement region data for gradation characteristic measurement; and animage output unit that outputs the gradation characteristic measurementsheet for gradation characteristic measurement based on image datacombined by the combining unit.
 6. The image forming apparatus accordingto claim 5, further comprising: a gradation correction data generationunit that generates gradation correction data for gradation correctionprocessing based on colorimetric data of gradation characteristicmeasurement regions; and a gradation correction unit that performsgradation correction processing on print data to be outputted to theimage output unit, based on the gradation correction data generated bythe gradation correction data generation unit.
 7. The image formingapparatus according to claim 5, wherein the identification informationincludes at least one of information to specify an image formingapparatus which has outputted the gradation characteristic measurementsheet, destination information, type information of the gradationcharacteristic measurement regions for gradation characteristicmeasurement, time information of time at which the gradationcharacteristic measurement sheet has been outputted, and information tospecify a subject tray or a subject sheet to which gradation correctionis to be applied.
 8. The image forming apparatus according to claim 6,wherein the identification information includes at least one ofinformation to specify an image forming apparatus which has outputtedthe gradation characteristic measurement sheet, destination information,type information of the gradation characteristic measurement regions forgradation characteristic measurement, time information of time at whichthe gradation characteristic measurement sheet has been outputted, andinformation to specify a subject tray or a subject sheet to whichgradation correction is to be applied.
 9. An image forming systemcomprising: a generation unit that generates identification informationmeasurement region data in which measurement regions are arrayed basedon identification information to identify a gradation characteristicmeasurement sheet for gradation characteristic measurement; a combiningunit that combines the identification information measurement regiondata generated by the generation unit with gradation characteristicmeasurement region data for gradation characteristic measurement; animage output unit that outputs the gradation characteristic measurementsheet for gradation characteristic measurement based on image datacombined by the combining unit; a colorimetry unit that performscolorimetry on color values of respective measurement regions on thegradation characteristic measurement sheet outputted by the image outputunit; and a determination unit that determines identificationinformation to identify the gradation characteristic measurement sheetbased on a result of colorimetry of identification informationmeasurement regions arranged to identify the gradation characteristicmeasurement sheet in a result of colorimetry by the colorimetry unit.10. A gradation characteristic measuring method comprising: performingcolorimetry on color values of respective measurement regions on agradation characteristic measurement sheet where the plurality ofmeasurement regions are formed in different densities; and determiningidentification information to identify the gradation characteristicmeasurement sheet based on a result of colorimetry of identificationinformation measurement regions arranged to identify the gradationcharacteristic measurement sheet in a result of colorimetry.
 11. Acomputer readable medium storing a program causing a computer to executea process for gradation characteristic measurement, the processcomprising: performing colorimetry on color values of respectivemeasurement regions on a gradation characteristic measurement sheetwhere the plurality of measurement regions are formed in differentdensities; and determining identification information to identify thegradation characteristic measurement sheet based on a result ofcolorimetry of identification information measurement regions arrangedto identify the gradation characteristic measurement sheet, in theresult of colorimetry.
 12. A gradation characteristic measurement sheetin which a plurality of gradation characteristic measurement regions forgradation characteristic measurement and identification informationmeasurement regions arrayed based on identification information toidentify the gradation characteristic measurement sheet are formed.